xref: /openbmc/linux/arch/powerpc/kernel/prom.c (revision 1f945a86)
1 /*
2  * Procedures for creating, accessing and interpreting the device tree.
3  *
4  * Paul Mackerras	August 1996.
5  * Copyright (C) 1996-2005 Paul Mackerras.
6  *
7  *  Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
8  *    {engebret|bergner}@us.ibm.com
9  *
10  *      This program is free software; you can redistribute it and/or
11  *      modify it under the terms of the GNU General Public License
12  *      as published by the Free Software Foundation; either version
13  *      2 of the License, or (at your option) any later version.
14  */
15 
16 #undef DEBUG
17 
18 #include <stdarg.h>
19 #include <linux/kernel.h>
20 #include <linux/string.h>
21 #include <linux/init.h>
22 #include <linux/threads.h>
23 #include <linux/spinlock.h>
24 #include <linux/types.h>
25 #include <linux/pci.h>
26 #include <linux/stringify.h>
27 #include <linux/delay.h>
28 #include <linux/initrd.h>
29 #include <linux/bitops.h>
30 #include <linux/module.h>
31 #include <linux/kexec.h>
32 #include <linux/debugfs.h>
33 #include <linux/irq.h>
34 
35 #include <asm/prom.h>
36 #include <asm/rtas.h>
37 #include <asm/lmb.h>
38 #include <asm/page.h>
39 #include <asm/processor.h>
40 #include <asm/irq.h>
41 #include <asm/io.h>
42 #include <asm/kdump.h>
43 #include <asm/smp.h>
44 #include <asm/system.h>
45 #include <asm/mmu.h>
46 #include <asm/pgtable.h>
47 #include <asm/pci.h>
48 #include <asm/iommu.h>
49 #include <asm/btext.h>
50 #include <asm/sections.h>
51 #include <asm/machdep.h>
52 #include <asm/pSeries_reconfig.h>
53 #include <asm/pci-bridge.h>
54 #include <asm/kexec.h>
55 #include <asm/system.h>
56 
57 #ifdef DEBUG
58 #define DBG(fmt...) printk(KERN_ERR fmt)
59 #else
60 #define DBG(fmt...)
61 #endif
62 
63 
64 static int __initdata dt_root_addr_cells;
65 static int __initdata dt_root_size_cells;
66 
67 #ifdef CONFIG_PPC64
68 int __initdata iommu_is_off;
69 int __initdata iommu_force_on;
70 unsigned long tce_alloc_start, tce_alloc_end;
71 #endif
72 
73 typedef u32 cell_t;
74 
75 #if 0
76 static struct boot_param_header *initial_boot_params __initdata;
77 #else
78 struct boot_param_header *initial_boot_params;
79 #endif
80 
81 static struct device_node *allnodes = NULL;
82 
83 /* use when traversing tree through the allnext, child, sibling,
84  * or parent members of struct device_node.
85  */
86 static DEFINE_RWLOCK(devtree_lock);
87 
88 /* export that to outside world */
89 struct device_node *of_chosen;
90 
91 static inline char *find_flat_dt_string(u32 offset)
92 {
93 	return ((char *)initial_boot_params) +
94 		initial_boot_params->off_dt_strings + offset;
95 }
96 
97 /**
98  * This function is used to scan the flattened device-tree, it is
99  * used to extract the memory informations at boot before we can
100  * unflatten the tree
101  */
102 int __init of_scan_flat_dt(int (*it)(unsigned long node,
103 				     const char *uname, int depth,
104 				     void *data),
105 			   void *data)
106 {
107 	unsigned long p = ((unsigned long)initial_boot_params) +
108 		initial_boot_params->off_dt_struct;
109 	int rc = 0;
110 	int depth = -1;
111 
112 	do {
113 		u32 tag = *((u32 *)p);
114 		char *pathp;
115 
116 		p += 4;
117 		if (tag == OF_DT_END_NODE) {
118 			depth --;
119 			continue;
120 		}
121 		if (tag == OF_DT_NOP)
122 			continue;
123 		if (tag == OF_DT_END)
124 			break;
125 		if (tag == OF_DT_PROP) {
126 			u32 sz = *((u32 *)p);
127 			p += 8;
128 			if (initial_boot_params->version < 0x10)
129 				p = _ALIGN(p, sz >= 8 ? 8 : 4);
130 			p += sz;
131 			p = _ALIGN(p, 4);
132 			continue;
133 		}
134 		if (tag != OF_DT_BEGIN_NODE) {
135 			printk(KERN_WARNING "Invalid tag %x scanning flattened"
136 			       " device tree !\n", tag);
137 			return -EINVAL;
138 		}
139 		depth++;
140 		pathp = (char *)p;
141 		p = _ALIGN(p + strlen(pathp) + 1, 4);
142 		if ((*pathp) == '/') {
143 			char *lp, *np;
144 			for (lp = NULL, np = pathp; *np; np++)
145 				if ((*np) == '/')
146 					lp = np+1;
147 			if (lp != NULL)
148 				pathp = lp;
149 		}
150 		rc = it(p, pathp, depth, data);
151 		if (rc != 0)
152 			break;
153 	} while(1);
154 
155 	return rc;
156 }
157 
158 unsigned long __init of_get_flat_dt_root(void)
159 {
160 	unsigned long p = ((unsigned long)initial_boot_params) +
161 		initial_boot_params->off_dt_struct;
162 
163 	while(*((u32 *)p) == OF_DT_NOP)
164 		p += 4;
165 	BUG_ON (*((u32 *)p) != OF_DT_BEGIN_NODE);
166 	p += 4;
167 	return _ALIGN(p + strlen((char *)p) + 1, 4);
168 }
169 
170 /**
171  * This  function can be used within scan_flattened_dt callback to get
172  * access to properties
173  */
174 void* __init of_get_flat_dt_prop(unsigned long node, const char *name,
175 				 unsigned long *size)
176 {
177 	unsigned long p = node;
178 
179 	do {
180 		u32 tag = *((u32 *)p);
181 		u32 sz, noff;
182 		const char *nstr;
183 
184 		p += 4;
185 		if (tag == OF_DT_NOP)
186 			continue;
187 		if (tag != OF_DT_PROP)
188 			return NULL;
189 
190 		sz = *((u32 *)p);
191 		noff = *((u32 *)(p + 4));
192 		p += 8;
193 		if (initial_boot_params->version < 0x10)
194 			p = _ALIGN(p, sz >= 8 ? 8 : 4);
195 
196 		nstr = find_flat_dt_string(noff);
197 		if (nstr == NULL) {
198 			printk(KERN_WARNING "Can't find property index"
199 			       " name !\n");
200 			return NULL;
201 		}
202 		if (strcmp(name, nstr) == 0) {
203 			if (size)
204 				*size = sz;
205 			return (void *)p;
206 		}
207 		p += sz;
208 		p = _ALIGN(p, 4);
209 	} while(1);
210 }
211 
212 int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
213 {
214 	const char* cp;
215 	unsigned long cplen, l;
216 
217 	cp = of_get_flat_dt_prop(node, "compatible", &cplen);
218 	if (cp == NULL)
219 		return 0;
220 	while (cplen > 0) {
221 		if (strncasecmp(cp, compat, strlen(compat)) == 0)
222 			return 1;
223 		l = strlen(cp) + 1;
224 		cp += l;
225 		cplen -= l;
226 	}
227 
228 	return 0;
229 }
230 
231 static void *__init unflatten_dt_alloc(unsigned long *mem, unsigned long size,
232 				       unsigned long align)
233 {
234 	void *res;
235 
236 	*mem = _ALIGN(*mem, align);
237 	res = (void *)*mem;
238 	*mem += size;
239 
240 	return res;
241 }
242 
243 static unsigned long __init unflatten_dt_node(unsigned long mem,
244 					      unsigned long *p,
245 					      struct device_node *dad,
246 					      struct device_node ***allnextpp,
247 					      unsigned long fpsize)
248 {
249 	struct device_node *np;
250 	struct property *pp, **prev_pp = NULL;
251 	char *pathp;
252 	u32 tag;
253 	unsigned int l, allocl;
254 	int has_name = 0;
255 	int new_format = 0;
256 
257 	tag = *((u32 *)(*p));
258 	if (tag != OF_DT_BEGIN_NODE) {
259 		printk("Weird tag at start of node: %x\n", tag);
260 		return mem;
261 	}
262 	*p += 4;
263 	pathp = (char *)*p;
264 	l = allocl = strlen(pathp) + 1;
265 	*p = _ALIGN(*p + l, 4);
266 
267 	/* version 0x10 has a more compact unit name here instead of the full
268 	 * path. we accumulate the full path size using "fpsize", we'll rebuild
269 	 * it later. We detect this because the first character of the name is
270 	 * not '/'.
271 	 */
272 	if ((*pathp) != '/') {
273 		new_format = 1;
274 		if (fpsize == 0) {
275 			/* root node: special case. fpsize accounts for path
276 			 * plus terminating zero. root node only has '/', so
277 			 * fpsize should be 2, but we want to avoid the first
278 			 * level nodes to have two '/' so we use fpsize 1 here
279 			 */
280 			fpsize = 1;
281 			allocl = 2;
282 		} else {
283 			/* account for '/' and path size minus terminal 0
284 			 * already in 'l'
285 			 */
286 			fpsize += l;
287 			allocl = fpsize;
288 		}
289 	}
290 
291 
292 	np = unflatten_dt_alloc(&mem, sizeof(struct device_node) + allocl,
293 				__alignof__(struct device_node));
294 	if (allnextpp) {
295 		memset(np, 0, sizeof(*np));
296 		np->full_name = ((char*)np) + sizeof(struct device_node);
297 		if (new_format) {
298 			char *p = np->full_name;
299 			/* rebuild full path for new format */
300 			if (dad && dad->parent) {
301 				strcpy(p, dad->full_name);
302 #ifdef DEBUG
303 				if ((strlen(p) + l + 1) != allocl) {
304 					DBG("%s: p: %d, l: %d, a: %d\n",
305 					    pathp, (int)strlen(p), l, allocl);
306 				}
307 #endif
308 				p += strlen(p);
309 			}
310 			*(p++) = '/';
311 			memcpy(p, pathp, l);
312 		} else
313 			memcpy(np->full_name, pathp, l);
314 		prev_pp = &np->properties;
315 		**allnextpp = np;
316 		*allnextpp = &np->allnext;
317 		if (dad != NULL) {
318 			np->parent = dad;
319 			/* we temporarily use the next field as `last_child'*/
320 			if (dad->next == 0)
321 				dad->child = np;
322 			else
323 				dad->next->sibling = np;
324 			dad->next = np;
325 		}
326 		kref_init(&np->kref);
327 	}
328 	while(1) {
329 		u32 sz, noff;
330 		char *pname;
331 
332 		tag = *((u32 *)(*p));
333 		if (tag == OF_DT_NOP) {
334 			*p += 4;
335 			continue;
336 		}
337 		if (tag != OF_DT_PROP)
338 			break;
339 		*p += 4;
340 		sz = *((u32 *)(*p));
341 		noff = *((u32 *)((*p) + 4));
342 		*p += 8;
343 		if (initial_boot_params->version < 0x10)
344 			*p = _ALIGN(*p, sz >= 8 ? 8 : 4);
345 
346 		pname = find_flat_dt_string(noff);
347 		if (pname == NULL) {
348 			printk("Can't find property name in list !\n");
349 			break;
350 		}
351 		if (strcmp(pname, "name") == 0)
352 			has_name = 1;
353 		l = strlen(pname) + 1;
354 		pp = unflatten_dt_alloc(&mem, sizeof(struct property),
355 					__alignof__(struct property));
356 		if (allnextpp) {
357 			if (strcmp(pname, "linux,phandle") == 0) {
358 				np->node = *((u32 *)*p);
359 				if (np->linux_phandle == 0)
360 					np->linux_phandle = np->node;
361 			}
362 			if (strcmp(pname, "ibm,phandle") == 0)
363 				np->linux_phandle = *((u32 *)*p);
364 			pp->name = pname;
365 			pp->length = sz;
366 			pp->value = (void *)*p;
367 			*prev_pp = pp;
368 			prev_pp = &pp->next;
369 		}
370 		*p = _ALIGN((*p) + sz, 4);
371 	}
372 	/* with version 0x10 we may not have the name property, recreate
373 	 * it here from the unit name if absent
374 	 */
375 	if (!has_name) {
376 		char *p = pathp, *ps = pathp, *pa = NULL;
377 		int sz;
378 
379 		while (*p) {
380 			if ((*p) == '@')
381 				pa = p;
382 			if ((*p) == '/')
383 				ps = p + 1;
384 			p++;
385 		}
386 		if (pa < ps)
387 			pa = p;
388 		sz = (pa - ps) + 1;
389 		pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz,
390 					__alignof__(struct property));
391 		if (allnextpp) {
392 			pp->name = "name";
393 			pp->length = sz;
394 			pp->value = pp + 1;
395 			*prev_pp = pp;
396 			prev_pp = &pp->next;
397 			memcpy(pp->value, ps, sz - 1);
398 			((char *)pp->value)[sz - 1] = 0;
399 			DBG("fixed up name for %s -> %s\n", pathp,
400 				(char *)pp->value);
401 		}
402 	}
403 	if (allnextpp) {
404 		*prev_pp = NULL;
405 		np->name = of_get_property(np, "name", NULL);
406 		np->type = of_get_property(np, "device_type", NULL);
407 
408 		if (!np->name)
409 			np->name = "<NULL>";
410 		if (!np->type)
411 			np->type = "<NULL>";
412 	}
413 	while (tag == OF_DT_BEGIN_NODE) {
414 		mem = unflatten_dt_node(mem, p, np, allnextpp, fpsize);
415 		tag = *((u32 *)(*p));
416 	}
417 	if (tag != OF_DT_END_NODE) {
418 		printk("Weird tag at end of node: %x\n", tag);
419 		return mem;
420 	}
421 	*p += 4;
422 	return mem;
423 }
424 
425 static int __init early_parse_mem(char *p)
426 {
427 	if (!p)
428 		return 1;
429 
430 	memory_limit = PAGE_ALIGN(memparse(p, &p));
431 	DBG("memory limit = 0x%lx\n", memory_limit);
432 
433 	return 0;
434 }
435 early_param("mem", early_parse_mem);
436 
437 /*
438  * The device tree may be allocated below our memory limit, or inside the
439  * crash kernel region for kdump. If so, move it out now.
440  */
441 static void move_device_tree(void)
442 {
443 	unsigned long start, size;
444 	void *p;
445 
446 	DBG("-> move_device_tree\n");
447 
448 	start = __pa(initial_boot_params);
449 	size = initial_boot_params->totalsize;
450 
451 	if ((memory_limit && (start + size) > memory_limit) ||
452 			overlaps_crashkernel(start, size)) {
453 		p = __va(lmb_alloc_base(size, PAGE_SIZE, lmb.rmo_size));
454 		memcpy(p, initial_boot_params, size);
455 		initial_boot_params = (struct boot_param_header *)p;
456 		DBG("Moved device tree to 0x%p\n", p);
457 	}
458 
459 	DBG("<- move_device_tree\n");
460 }
461 
462 /**
463  * unflattens the device-tree passed by the firmware, creating the
464  * tree of struct device_node. It also fills the "name" and "type"
465  * pointers of the nodes so the normal device-tree walking functions
466  * can be used (this used to be done by finish_device_tree)
467  */
468 void __init unflatten_device_tree(void)
469 {
470 	unsigned long start, mem, size;
471 	struct device_node **allnextp = &allnodes;
472 
473 	DBG(" -> unflatten_device_tree()\n");
474 
475 	/* First pass, scan for size */
476 	start = ((unsigned long)initial_boot_params) +
477 		initial_boot_params->off_dt_struct;
478 	size = unflatten_dt_node(0, &start, NULL, NULL, 0);
479 	size = (size | 3) + 1;
480 
481 	DBG("  size is %lx, allocating...\n", size);
482 
483 	/* Allocate memory for the expanded device tree */
484 	mem = lmb_alloc(size + 4, __alignof__(struct device_node));
485 	mem = (unsigned long) __va(mem);
486 
487 	((u32 *)mem)[size / 4] = 0xdeadbeef;
488 
489 	DBG("  unflattening %lx...\n", mem);
490 
491 	/* Second pass, do actual unflattening */
492 	start = ((unsigned long)initial_boot_params) +
493 		initial_boot_params->off_dt_struct;
494 	unflatten_dt_node(mem, &start, NULL, &allnextp, 0);
495 	if (*((u32 *)start) != OF_DT_END)
496 		printk(KERN_WARNING "Weird tag at end of tree: %08x\n", *((u32 *)start));
497 	if (((u32 *)mem)[size / 4] != 0xdeadbeef)
498 		printk(KERN_WARNING "End of tree marker overwritten: %08x\n",
499 		       ((u32 *)mem)[size / 4] );
500 	*allnextp = NULL;
501 
502 	/* Get pointer to OF "/chosen" node for use everywhere */
503 	of_chosen = of_find_node_by_path("/chosen");
504 	if (of_chosen == NULL)
505 		of_chosen = of_find_node_by_path("/chosen@0");
506 
507 	DBG(" <- unflatten_device_tree()\n");
508 }
509 
510 /*
511  * ibm,pa-features is a per-cpu property that contains a string of
512  * attribute descriptors, each of which has a 2 byte header plus up
513  * to 254 bytes worth of processor attribute bits.  First header
514  * byte specifies the number of bytes following the header.
515  * Second header byte is an "attribute-specifier" type, of which
516  * zero is the only currently-defined value.
517  * Implementation:  Pass in the byte and bit offset for the feature
518  * that we are interested in.  The function will return -1 if the
519  * pa-features property is missing, or a 1/0 to indicate if the feature
520  * is supported/not supported.  Note that the bit numbers are
521  * big-endian to match the definition in PAPR.
522  */
523 static struct ibm_pa_feature {
524 	unsigned long	cpu_features;	/* CPU_FTR_xxx bit */
525 	unsigned int	cpu_user_ftrs;	/* PPC_FEATURE_xxx bit */
526 	unsigned char	pabyte;		/* byte number in ibm,pa-features */
527 	unsigned char	pabit;		/* bit number (big-endian) */
528 	unsigned char	invert;		/* if 1, pa bit set => clear feature */
529 } ibm_pa_features[] __initdata = {
530 	{0, PPC_FEATURE_HAS_MMU,	0, 0, 0},
531 	{0, PPC_FEATURE_HAS_FPU,	0, 1, 0},
532 	{CPU_FTR_SLB, 0,		0, 2, 0},
533 	{CPU_FTR_CTRL, 0,		0, 3, 0},
534 	{CPU_FTR_NOEXECUTE, 0,		0, 6, 0},
535 	{CPU_FTR_NODSISRALIGN, 0,	1, 1, 1},
536 #if 0
537 	/* put this back once we know how to test if firmware does 64k IO */
538 	{CPU_FTR_CI_LARGE_PAGE, 0,	1, 2, 0},
539 #endif
540 	{CPU_FTR_REAL_LE, PPC_FEATURE_TRUE_LE, 5, 0, 0},
541 };
542 
543 static void __init scan_features(unsigned long node, unsigned char *ftrs,
544 				 unsigned long tablelen,
545 				 struct ibm_pa_feature *fp,
546 				 unsigned long ft_size)
547 {
548 	unsigned long i, len, bit;
549 
550 	/* find descriptor with type == 0 */
551 	for (;;) {
552 		if (tablelen < 3)
553 			return;
554 		len = 2 + ftrs[0];
555 		if (tablelen < len)
556 			return;		/* descriptor 0 not found */
557 		if (ftrs[1] == 0)
558 			break;
559 		tablelen -= len;
560 		ftrs += len;
561 	}
562 
563 	/* loop over bits we know about */
564 	for (i = 0; i < ft_size; ++i, ++fp) {
565 		if (fp->pabyte >= ftrs[0])
566 			continue;
567 		bit = (ftrs[2 + fp->pabyte] >> (7 - fp->pabit)) & 1;
568 		if (bit ^ fp->invert) {
569 			cur_cpu_spec->cpu_features |= fp->cpu_features;
570 			cur_cpu_spec->cpu_user_features |= fp->cpu_user_ftrs;
571 		} else {
572 			cur_cpu_spec->cpu_features &= ~fp->cpu_features;
573 			cur_cpu_spec->cpu_user_features &= ~fp->cpu_user_ftrs;
574 		}
575 	}
576 }
577 
578 static void __init check_cpu_pa_features(unsigned long node)
579 {
580 	unsigned char *pa_ftrs;
581 	unsigned long tablelen;
582 
583 	pa_ftrs = of_get_flat_dt_prop(node, "ibm,pa-features", &tablelen);
584 	if (pa_ftrs == NULL)
585 		return;
586 
587 	scan_features(node, pa_ftrs, tablelen,
588 		      ibm_pa_features, ARRAY_SIZE(ibm_pa_features));
589 }
590 
591 static struct feature_property {
592 	const char *name;
593 	u32 min_value;
594 	unsigned long cpu_feature;
595 	unsigned long cpu_user_ftr;
596 } feature_properties[] __initdata = {
597 #ifdef CONFIG_ALTIVEC
598 	{"altivec", 0, CPU_FTR_ALTIVEC, PPC_FEATURE_HAS_ALTIVEC},
599 	{"ibm,vmx", 1, CPU_FTR_ALTIVEC, PPC_FEATURE_HAS_ALTIVEC},
600 #endif /* CONFIG_ALTIVEC */
601 #ifdef CONFIG_PPC64
602 	{"ibm,dfp", 1, 0, PPC_FEATURE_HAS_DFP},
603 	{"ibm,purr", 1, CPU_FTR_PURR, 0},
604 	{"ibm,spurr", 1, CPU_FTR_SPURR, 0},
605 #endif /* CONFIG_PPC64 */
606 };
607 
608 static void __init check_cpu_feature_properties(unsigned long node)
609 {
610 	unsigned long i;
611 	struct feature_property *fp = feature_properties;
612 	const u32 *prop;
613 
614 	for (i = 0; i < ARRAY_SIZE(feature_properties); ++i, ++fp) {
615 		prop = of_get_flat_dt_prop(node, fp->name, NULL);
616 		if (prop && *prop >= fp->min_value) {
617 			cur_cpu_spec->cpu_features |= fp->cpu_feature;
618 			cur_cpu_spec->cpu_user_features |= fp->cpu_user_ftr;
619 		}
620 	}
621 }
622 
623 static int __init early_init_dt_scan_cpus(unsigned long node,
624 					  const char *uname, int depth,
625 					  void *data)
626 {
627 	static int logical_cpuid = 0;
628 	char *type = of_get_flat_dt_prop(node, "device_type", NULL);
629 	const u32 *prop;
630 	const u32 *intserv;
631 	int i, nthreads;
632 	unsigned long len;
633 	int found = 0;
634 
635 	/* We are scanning "cpu" nodes only */
636 	if (type == NULL || strcmp(type, "cpu") != 0)
637 		return 0;
638 
639 	/* Get physical cpuid */
640 	intserv = of_get_flat_dt_prop(node, "ibm,ppc-interrupt-server#s", &len);
641 	if (intserv) {
642 		nthreads = len / sizeof(int);
643 	} else {
644 		intserv = of_get_flat_dt_prop(node, "reg", NULL);
645 		nthreads = 1;
646 	}
647 
648 	/*
649 	 * Now see if any of these threads match our boot cpu.
650 	 * NOTE: This must match the parsing done in smp_setup_cpu_maps.
651 	 */
652 	for (i = 0; i < nthreads; i++) {
653 		/*
654 		 * version 2 of the kexec param format adds the phys cpuid of
655 		 * booted proc.
656 		 */
657 		if (initial_boot_params && initial_boot_params->version >= 2) {
658 			if (intserv[i] ==
659 					initial_boot_params->boot_cpuid_phys) {
660 				found = 1;
661 				break;
662 			}
663 		} else {
664 			/*
665 			 * Check if it's the boot-cpu, set it's hw index now,
666 			 * unfortunately this format did not support booting
667 			 * off secondary threads.
668 			 */
669 			if (of_get_flat_dt_prop(node,
670 					"linux,boot-cpu", NULL) != NULL) {
671 				found = 1;
672 				break;
673 			}
674 		}
675 
676 #ifdef CONFIG_SMP
677 		/* logical cpu id is always 0 on UP kernels */
678 		logical_cpuid++;
679 #endif
680 	}
681 
682 	if (found) {
683 		DBG("boot cpu: logical %d physical %d\n", logical_cpuid,
684 			intserv[i]);
685 		boot_cpuid = logical_cpuid;
686 		set_hard_smp_processor_id(boot_cpuid, intserv[i]);
687 
688 		/*
689 		 * PAPR defines "logical" PVR values for cpus that
690 		 * meet various levels of the architecture:
691 		 * 0x0f000001	Architecture version 2.04
692 		 * 0x0f000002	Architecture version 2.05
693 		 * If the cpu-version property in the cpu node contains
694 		 * such a value, we call identify_cpu again with the
695 		 * logical PVR value in order to use the cpu feature
696 		 * bits appropriate for the architecture level.
697 		 *
698 		 * A POWER6 partition in "POWER6 architected" mode
699 		 * uses the 0x0f000002 PVR value; in POWER5+ mode
700 		 * it uses 0x0f000001.
701 		 */
702 		prop = of_get_flat_dt_prop(node, "cpu-version", NULL);
703 		if (prop && (*prop & 0xff000000) == 0x0f000000)
704 			identify_cpu(0, *prop);
705 	}
706 
707 	check_cpu_feature_properties(node);
708 	check_cpu_pa_features(node);
709 
710 #ifdef CONFIG_PPC_PSERIES
711 	if (nthreads > 1)
712 		cur_cpu_spec->cpu_features |= CPU_FTR_SMT;
713 	else
714 		cur_cpu_spec->cpu_features &= ~CPU_FTR_SMT;
715 #endif
716 
717 	return 0;
718 }
719 
720 #ifdef CONFIG_BLK_DEV_INITRD
721 static void __init early_init_dt_check_for_initrd(unsigned long node)
722 {
723 	unsigned long l;
724 	u32 *prop;
725 
726 	DBG("Looking for initrd properties... ");
727 
728 	prop = of_get_flat_dt_prop(node, "linux,initrd-start", &l);
729 	if (prop) {
730 		initrd_start = (unsigned long)__va(of_read_ulong(prop, l/4));
731 
732 		prop = of_get_flat_dt_prop(node, "linux,initrd-end", &l);
733 		if (prop) {
734 			initrd_end = (unsigned long)
735 					__va(of_read_ulong(prop, l/4));
736 			initrd_below_start_ok = 1;
737 		} else {
738 			initrd_start = 0;
739 		}
740 	}
741 
742 	DBG("initrd_start=0x%lx  initrd_end=0x%lx\n", initrd_start, initrd_end);
743 }
744 #else
745 static inline void early_init_dt_check_for_initrd(unsigned long node)
746 {
747 }
748 #endif /* CONFIG_BLK_DEV_INITRD */
749 
750 static int __init early_init_dt_scan_chosen(unsigned long node,
751 					    const char *uname, int depth, void *data)
752 {
753 	unsigned long *lprop;
754 	unsigned long l;
755 	char *p;
756 
757 	DBG("search \"chosen\", depth: %d, uname: %s\n", depth, uname);
758 
759 	if (depth != 1 ||
760 	    (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
761 		return 0;
762 
763 #ifdef CONFIG_PPC64
764 	/* check if iommu is forced on or off */
765 	if (of_get_flat_dt_prop(node, "linux,iommu-off", NULL) != NULL)
766 		iommu_is_off = 1;
767 	if (of_get_flat_dt_prop(node, "linux,iommu-force-on", NULL) != NULL)
768 		iommu_force_on = 1;
769 #endif
770 
771 	/* mem=x on the command line is the preferred mechanism */
772  	lprop = of_get_flat_dt_prop(node, "linux,memory-limit", NULL);
773  	if (lprop)
774  		memory_limit = *lprop;
775 
776 #ifdef CONFIG_PPC64
777  	lprop = of_get_flat_dt_prop(node, "linux,tce-alloc-start", NULL);
778  	if (lprop)
779  		tce_alloc_start = *lprop;
780  	lprop = of_get_flat_dt_prop(node, "linux,tce-alloc-end", NULL);
781  	if (lprop)
782  		tce_alloc_end = *lprop;
783 #endif
784 
785 #ifdef CONFIG_KEXEC
786        lprop = (u64*)of_get_flat_dt_prop(node, "linux,crashkernel-base", NULL);
787        if (lprop)
788                crashk_res.start = *lprop;
789 
790        lprop = (u64*)of_get_flat_dt_prop(node, "linux,crashkernel-size", NULL);
791        if (lprop)
792                crashk_res.end = crashk_res.start + *lprop - 1;
793 #endif
794 
795 	early_init_dt_check_for_initrd(node);
796 
797 	/* Retreive command line */
798  	p = of_get_flat_dt_prop(node, "bootargs", &l);
799 	if (p != NULL && l > 0)
800 		strlcpy(cmd_line, p, min((int)l, COMMAND_LINE_SIZE));
801 
802 #ifdef CONFIG_CMDLINE
803 	if (p == NULL || l == 0 || (l == 1 && (*p) == 0))
804 		strlcpy(cmd_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
805 #endif /* CONFIG_CMDLINE */
806 
807 	DBG("Command line is: %s\n", cmd_line);
808 
809 	/* break now */
810 	return 1;
811 }
812 
813 static int __init early_init_dt_scan_root(unsigned long node,
814 					  const char *uname, int depth, void *data)
815 {
816 	u32 *prop;
817 
818 	if (depth != 0)
819 		return 0;
820 
821 	prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
822 	dt_root_size_cells = (prop == NULL) ? 1 : *prop;
823 	DBG("dt_root_size_cells = %x\n", dt_root_size_cells);
824 
825 	prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
826 	dt_root_addr_cells = (prop == NULL) ? 2 : *prop;
827 	DBG("dt_root_addr_cells = %x\n", dt_root_addr_cells);
828 
829 	/* break now */
830 	return 1;
831 }
832 
833 static unsigned long __init dt_mem_next_cell(int s, cell_t **cellp)
834 {
835 	cell_t *p = *cellp;
836 
837 	*cellp = p + s;
838 	return of_read_ulong(p, s);
839 }
840 
841 #ifdef CONFIG_PPC_PSERIES
842 /*
843  * Interpret the ibm,dynamic-memory property in the
844  * /ibm,dynamic-reconfiguration-memory node.
845  * This contains a list of memory blocks along with NUMA affinity
846  * information.
847  */
848 static int __init early_init_dt_scan_drconf_memory(unsigned long node)
849 {
850 	cell_t *dm, *ls;
851 	unsigned long l, n;
852 	unsigned long base, size, lmb_size, flags;
853 
854 	ls = (cell_t *)of_get_flat_dt_prop(node, "ibm,lmb-size", &l);
855 	if (ls == NULL || l < dt_root_size_cells * sizeof(cell_t))
856 		return 0;
857 	lmb_size = dt_mem_next_cell(dt_root_size_cells, &ls);
858 
859 	dm = (cell_t *)of_get_flat_dt_prop(node, "ibm,dynamic-memory", &l);
860 	if (dm == NULL || l < sizeof(cell_t))
861 		return 0;
862 
863 	n = *dm++;	/* number of entries */
864 	if (l < (n * (dt_root_addr_cells + 4) + 1) * sizeof(cell_t))
865 		return 0;
866 
867 	for (; n != 0; --n) {
868 		base = dt_mem_next_cell(dt_root_addr_cells, &dm);
869 		flags = dm[3];
870 		/* skip DRC index, pad, assoc. list index, flags */
871 		dm += 4;
872 		/* skip this block if the reserved bit is set in flags (0x80)
873 		   or if the block is not assigned to this partition (0x8) */
874 		if ((flags & 0x80) || !(flags & 0x8))
875 			continue;
876 		size = lmb_size;
877 		if (iommu_is_off) {
878 			if (base >= 0x80000000ul)
879 				continue;
880 			if ((base + size) > 0x80000000ul)
881 				size = 0x80000000ul - base;
882 		}
883 		lmb_add(base, size);
884 	}
885 	lmb_dump_all();
886 	return 0;
887 }
888 #else
889 #define early_init_dt_scan_drconf_memory(node)	0
890 #endif /* CONFIG_PPC_PSERIES */
891 
892 static int __init early_init_dt_scan_memory(unsigned long node,
893 					    const char *uname, int depth, void *data)
894 {
895 	char *type = of_get_flat_dt_prop(node, "device_type", NULL);
896 	cell_t *reg, *endp;
897 	unsigned long l;
898 
899 	/* Look for the ibm,dynamic-reconfiguration-memory node */
900 	if (depth == 1 &&
901 	    strcmp(uname, "ibm,dynamic-reconfiguration-memory") == 0)
902 		return early_init_dt_scan_drconf_memory(node);
903 
904 	/* We are scanning "memory" nodes only */
905 	if (type == NULL) {
906 		/*
907 		 * The longtrail doesn't have a device_type on the
908 		 * /memory node, so look for the node called /memory@0.
909 		 */
910 		if (depth != 1 || strcmp(uname, "memory@0") != 0)
911 			return 0;
912 	} else if (strcmp(type, "memory") != 0)
913 		return 0;
914 
915 	reg = (cell_t *)of_get_flat_dt_prop(node, "linux,usable-memory", &l);
916 	if (reg == NULL)
917 		reg = (cell_t *)of_get_flat_dt_prop(node, "reg", &l);
918 	if (reg == NULL)
919 		return 0;
920 
921 	endp = reg + (l / sizeof(cell_t));
922 
923 	DBG("memory scan node %s, reg size %ld, data: %x %x %x %x,\n",
924 	    uname, l, reg[0], reg[1], reg[2], reg[3]);
925 
926 	while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
927 		unsigned long base, size;
928 
929 		base = dt_mem_next_cell(dt_root_addr_cells, &reg);
930 		size = dt_mem_next_cell(dt_root_size_cells, &reg);
931 
932 		if (size == 0)
933 			continue;
934 		DBG(" - %lx ,  %lx\n", base, size);
935 #ifdef CONFIG_PPC64
936 		if (iommu_is_off) {
937 			if (base >= 0x80000000ul)
938 				continue;
939 			if ((base + size) > 0x80000000ul)
940 				size = 0x80000000ul - base;
941 		}
942 #endif
943 		lmb_add(base, size);
944 	}
945 	return 0;
946 }
947 
948 static void __init early_reserve_mem(void)
949 {
950 	u64 base, size;
951 	u64 *reserve_map;
952 	unsigned long self_base;
953 	unsigned long self_size;
954 
955 	reserve_map = (u64 *)(((unsigned long)initial_boot_params) +
956 					initial_boot_params->off_mem_rsvmap);
957 
958 	/* before we do anything, lets reserve the dt blob */
959 	self_base = __pa((unsigned long)initial_boot_params);
960 	self_size = initial_boot_params->totalsize;
961 	lmb_reserve(self_base, self_size);
962 
963 #ifdef CONFIG_BLK_DEV_INITRD
964 	/* then reserve the initrd, if any */
965 	if (initrd_start && (initrd_end > initrd_start))
966 		lmb_reserve(__pa(initrd_start), initrd_end - initrd_start);
967 #endif /* CONFIG_BLK_DEV_INITRD */
968 
969 #ifdef CONFIG_PPC32
970 	/*
971 	 * Handle the case where we might be booting from an old kexec
972 	 * image that setup the mem_rsvmap as pairs of 32-bit values
973 	 */
974 	if (*reserve_map > 0xffffffffull) {
975 		u32 base_32, size_32;
976 		u32 *reserve_map_32 = (u32 *)reserve_map;
977 
978 		while (1) {
979 			base_32 = *(reserve_map_32++);
980 			size_32 = *(reserve_map_32++);
981 			if (size_32 == 0)
982 				break;
983 			/* skip if the reservation is for the blob */
984 			if (base_32 == self_base && size_32 == self_size)
985 				continue;
986 			DBG("reserving: %x -> %x\n", base_32, size_32);
987 			lmb_reserve(base_32, size_32);
988 		}
989 		return;
990 	}
991 #endif
992 	while (1) {
993 		base = *(reserve_map++);
994 		size = *(reserve_map++);
995 		if (size == 0)
996 			break;
997 		DBG("reserving: %llx -> %llx\n", base, size);
998 		lmb_reserve(base, size);
999 	}
1000 
1001 #if 0
1002 	DBG("memory reserved, lmbs :\n");
1003       	lmb_dump_all();
1004 #endif
1005 }
1006 
1007 void __init early_init_devtree(void *params)
1008 {
1009 	DBG(" -> early_init_devtree(%p)\n", params);
1010 
1011 	/* Setup flat device-tree pointer */
1012 	initial_boot_params = params;
1013 
1014 #ifdef CONFIG_PPC_RTAS
1015 	/* Some machines might need RTAS info for debugging, grab it now. */
1016 	of_scan_flat_dt(early_init_dt_scan_rtas, NULL);
1017 #endif
1018 
1019 	/* Retrieve various informations from the /chosen node of the
1020 	 * device-tree, including the platform type, initrd location and
1021 	 * size, TCE reserve, and more ...
1022 	 */
1023 	of_scan_flat_dt(early_init_dt_scan_chosen, NULL);
1024 
1025 	/* Scan memory nodes and rebuild LMBs */
1026 	lmb_init();
1027 	of_scan_flat_dt(early_init_dt_scan_root, NULL);
1028 	of_scan_flat_dt(early_init_dt_scan_memory, NULL);
1029 
1030 	/* Save command line for /proc/cmdline and then parse parameters */
1031 	strlcpy(boot_command_line, cmd_line, COMMAND_LINE_SIZE);
1032 	parse_early_param();
1033 
1034 	/* Reserve LMB regions used by kernel, initrd, dt, etc... */
1035 	lmb_reserve(PHYSICAL_START, __pa(klimit) - PHYSICAL_START);
1036 	reserve_kdump_trampoline();
1037 	reserve_crashkernel();
1038 	early_reserve_mem();
1039 
1040 	lmb_enforce_memory_limit(memory_limit);
1041 	lmb_analyze();
1042 
1043 	DBG("Phys. mem: %lx\n", lmb_phys_mem_size());
1044 
1045 	/* We may need to relocate the flat tree, do it now.
1046 	 * FIXME .. and the initrd too? */
1047 	move_device_tree();
1048 
1049 	DBG("Scanning CPUs ...\n");
1050 
1051 	/* Retreive CPU related informations from the flat tree
1052 	 * (altivec support, boot CPU ID, ...)
1053 	 */
1054 	of_scan_flat_dt(early_init_dt_scan_cpus, NULL);
1055 
1056 	DBG(" <- early_init_devtree()\n");
1057 }
1058 
1059 int of_n_addr_cells(struct device_node* np)
1060 {
1061 	const int *ip;
1062 	do {
1063 		if (np->parent)
1064 			np = np->parent;
1065 		ip = of_get_property(np, "#address-cells", NULL);
1066 		if (ip != NULL)
1067 			return *ip;
1068 	} while (np->parent);
1069 	/* No #address-cells property for the root node, default to 1 */
1070 	return 1;
1071 }
1072 EXPORT_SYMBOL(of_n_addr_cells);
1073 
1074 int of_n_size_cells(struct device_node* np)
1075 {
1076 	const int* ip;
1077 	do {
1078 		if (np->parent)
1079 			np = np->parent;
1080 		ip = of_get_property(np, "#size-cells", NULL);
1081 		if (ip != NULL)
1082 			return *ip;
1083 	} while (np->parent);
1084 	/* No #size-cells property for the root node, default to 1 */
1085 	return 1;
1086 }
1087 EXPORT_SYMBOL(of_n_size_cells);
1088 
1089 /** Checks if the given "compat" string matches one of the strings in
1090  * the device's "compatible" property
1091  */
1092 int of_device_is_compatible(const struct device_node *device,
1093 		const char *compat)
1094 {
1095 	const char* cp;
1096 	int cplen, l;
1097 
1098 	cp = of_get_property(device, "compatible", &cplen);
1099 	if (cp == NULL)
1100 		return 0;
1101 	while (cplen > 0) {
1102 		if (strncasecmp(cp, compat, strlen(compat)) == 0)
1103 			return 1;
1104 		l = strlen(cp) + 1;
1105 		cp += l;
1106 		cplen -= l;
1107 	}
1108 
1109 	return 0;
1110 }
1111 EXPORT_SYMBOL(of_device_is_compatible);
1112 
1113 
1114 /**
1115  * Indicates whether the root node has a given value in its
1116  * compatible property.
1117  */
1118 int machine_is_compatible(const char *compat)
1119 {
1120 	struct device_node *root;
1121 	int rc = 0;
1122 
1123 	root = of_find_node_by_path("/");
1124 	if (root) {
1125 		rc = of_device_is_compatible(root, compat);
1126 		of_node_put(root);
1127 	}
1128 	return rc;
1129 }
1130 EXPORT_SYMBOL(machine_is_compatible);
1131 
1132 /*******
1133  *
1134  * New implementation of the OF "find" APIs, return a refcounted
1135  * object, call of_node_put() when done.  The device tree and list
1136  * are protected by a rw_lock.
1137  *
1138  * Note that property management will need some locking as well,
1139  * this isn't dealt with yet.
1140  *
1141  *******/
1142 
1143 /**
1144  *	of_find_node_by_name - Find a node by its "name" property
1145  *	@from:	The node to start searching from or NULL, the node
1146  *		you pass will not be searched, only the next one
1147  *		will; typically, you pass what the previous call
1148  *		returned. of_node_put() will be called on it
1149  *	@name:	The name string to match against
1150  *
1151  *	Returns a node pointer with refcount incremented, use
1152  *	of_node_put() on it when done.
1153  */
1154 struct device_node *of_find_node_by_name(struct device_node *from,
1155 	const char *name)
1156 {
1157 	struct device_node *np;
1158 
1159 	read_lock(&devtree_lock);
1160 	np = from ? from->allnext : allnodes;
1161 	for (; np != NULL; np = np->allnext)
1162 		if (np->name != NULL && strcasecmp(np->name, name) == 0
1163 		    && of_node_get(np))
1164 			break;
1165 	of_node_put(from);
1166 	read_unlock(&devtree_lock);
1167 	return np;
1168 }
1169 EXPORT_SYMBOL(of_find_node_by_name);
1170 
1171 /**
1172  *	of_find_node_by_type - Find a node by its "device_type" property
1173  *	@from:	The node to start searching from, or NULL to start searching
1174  *		the entire device tree. The node you pass will not be
1175  *		searched, only the next one will; typically, you pass
1176  *		what the previous call returned. of_node_put() will be
1177  *		called on from for you.
1178  *	@type:	The type string to match against
1179  *
1180  *	Returns a node pointer with refcount incremented, use
1181  *	of_node_put() on it when done.
1182  */
1183 struct device_node *of_find_node_by_type(struct device_node *from,
1184 	const char *type)
1185 {
1186 	struct device_node *np;
1187 
1188 	read_lock(&devtree_lock);
1189 	np = from ? from->allnext : allnodes;
1190 	for (; np != 0; np = np->allnext)
1191 		if (np->type != 0 && strcasecmp(np->type, type) == 0
1192 		    && of_node_get(np))
1193 			break;
1194 	of_node_put(from);
1195 	read_unlock(&devtree_lock);
1196 	return np;
1197 }
1198 EXPORT_SYMBOL(of_find_node_by_type);
1199 
1200 /**
1201  *	of_find_compatible_node - Find a node based on type and one of the
1202  *                                tokens in its "compatible" property
1203  *	@from:		The node to start searching from or NULL, the node
1204  *			you pass will not be searched, only the next one
1205  *			will; typically, you pass what the previous call
1206  *			returned. of_node_put() will be called on it
1207  *	@type:		The type string to match "device_type" or NULL to ignore
1208  *	@compatible:	The string to match to one of the tokens in the device
1209  *			"compatible" list.
1210  *
1211  *	Returns a node pointer with refcount incremented, use
1212  *	of_node_put() on it when done.
1213  */
1214 struct device_node *of_find_compatible_node(struct device_node *from,
1215 	const char *type, const char *compatible)
1216 {
1217 	struct device_node *np;
1218 
1219 	read_lock(&devtree_lock);
1220 	np = from ? from->allnext : allnodes;
1221 	for (; np != 0; np = np->allnext) {
1222 		if (type != NULL
1223 		    && !(np->type != 0 && strcasecmp(np->type, type) == 0))
1224 			continue;
1225 		if (of_device_is_compatible(np, compatible) && of_node_get(np))
1226 			break;
1227 	}
1228 	of_node_put(from);
1229 	read_unlock(&devtree_lock);
1230 	return np;
1231 }
1232 EXPORT_SYMBOL(of_find_compatible_node);
1233 
1234 /**
1235  *	of_find_node_by_path - Find a node matching a full OF path
1236  *	@path:	The full path to match
1237  *
1238  *	Returns a node pointer with refcount incremented, use
1239  *	of_node_put() on it when done.
1240  */
1241 struct device_node *of_find_node_by_path(const char *path)
1242 {
1243 	struct device_node *np = allnodes;
1244 
1245 	read_lock(&devtree_lock);
1246 	for (; np != 0; np = np->allnext) {
1247 		if (np->full_name != 0 && strcasecmp(np->full_name, path) == 0
1248 		    && of_node_get(np))
1249 			break;
1250 	}
1251 	read_unlock(&devtree_lock);
1252 	return np;
1253 }
1254 EXPORT_SYMBOL(of_find_node_by_path);
1255 
1256 /**
1257  *	of_find_node_by_phandle - Find a node given a phandle
1258  *	@handle:	phandle of the node to find
1259  *
1260  *	Returns a node pointer with refcount incremented, use
1261  *	of_node_put() on it when done.
1262  */
1263 struct device_node *of_find_node_by_phandle(phandle handle)
1264 {
1265 	struct device_node *np;
1266 
1267 	read_lock(&devtree_lock);
1268 	for (np = allnodes; np != 0; np = np->allnext)
1269 		if (np->linux_phandle == handle)
1270 			break;
1271 	of_node_get(np);
1272 	read_unlock(&devtree_lock);
1273 	return np;
1274 }
1275 EXPORT_SYMBOL(of_find_node_by_phandle);
1276 
1277 /**
1278  *	of_find_all_nodes - Get next node in global list
1279  *	@prev:	Previous node or NULL to start iteration
1280  *		of_node_put() will be called on it
1281  *
1282  *	Returns a node pointer with refcount incremented, use
1283  *	of_node_put() on it when done.
1284  */
1285 struct device_node *of_find_all_nodes(struct device_node *prev)
1286 {
1287 	struct device_node *np;
1288 
1289 	read_lock(&devtree_lock);
1290 	np = prev ? prev->allnext : allnodes;
1291 	for (; np != 0; np = np->allnext)
1292 		if (of_node_get(np))
1293 			break;
1294 	of_node_put(prev);
1295 	read_unlock(&devtree_lock);
1296 	return np;
1297 }
1298 EXPORT_SYMBOL(of_find_all_nodes);
1299 
1300 /**
1301  *	of_get_parent - Get a node's parent if any
1302  *	@node:	Node to get parent
1303  *
1304  *	Returns a node pointer with refcount incremented, use
1305  *	of_node_put() on it when done.
1306  */
1307 struct device_node *of_get_parent(const struct device_node *node)
1308 {
1309 	struct device_node *np;
1310 
1311 	if (!node)
1312 		return NULL;
1313 
1314 	read_lock(&devtree_lock);
1315 	np = of_node_get(node->parent);
1316 	read_unlock(&devtree_lock);
1317 	return np;
1318 }
1319 EXPORT_SYMBOL(of_get_parent);
1320 
1321 /**
1322  *	of_get_next_child - Iterate a node childs
1323  *	@node:	parent node
1324  *	@prev:	previous child of the parent node, or NULL to get first
1325  *
1326  *	Returns a node pointer with refcount incremented, use
1327  *	of_node_put() on it when done.
1328  */
1329 struct device_node *of_get_next_child(const struct device_node *node,
1330 	struct device_node *prev)
1331 {
1332 	struct device_node *next;
1333 
1334 	read_lock(&devtree_lock);
1335 	next = prev ? prev->sibling : node->child;
1336 	for (; next != 0; next = next->sibling)
1337 		if (of_node_get(next))
1338 			break;
1339 	of_node_put(prev);
1340 	read_unlock(&devtree_lock);
1341 	return next;
1342 }
1343 EXPORT_SYMBOL(of_get_next_child);
1344 
1345 /**
1346  *	of_node_get - Increment refcount of a node
1347  *	@node:	Node to inc refcount, NULL is supported to
1348  *		simplify writing of callers
1349  *
1350  *	Returns node.
1351  */
1352 struct device_node *of_node_get(struct device_node *node)
1353 {
1354 	if (node)
1355 		kref_get(&node->kref);
1356 	return node;
1357 }
1358 EXPORT_SYMBOL(of_node_get);
1359 
1360 static inline struct device_node * kref_to_device_node(struct kref *kref)
1361 {
1362 	return container_of(kref, struct device_node, kref);
1363 }
1364 
1365 /**
1366  *	of_node_release - release a dynamically allocated node
1367  *	@kref:  kref element of the node to be released
1368  *
1369  *	In of_node_put() this function is passed to kref_put()
1370  *	as the destructor.
1371  */
1372 static void of_node_release(struct kref *kref)
1373 {
1374 	struct device_node *node = kref_to_device_node(kref);
1375 	struct property *prop = node->properties;
1376 
1377 	/* We should never be releasing nodes that haven't been detached. */
1378 	if (!of_node_check_flag(node, OF_DETACHED)) {
1379 		printk("WARNING: Bad of_node_put() on %s\n", node->full_name);
1380 		dump_stack();
1381 		kref_init(&node->kref);
1382 		return;
1383 	}
1384 
1385 	if (!of_node_check_flag(node, OF_DYNAMIC))
1386 		return;
1387 
1388 	while (prop) {
1389 		struct property *next = prop->next;
1390 		kfree(prop->name);
1391 		kfree(prop->value);
1392 		kfree(prop);
1393 		prop = next;
1394 
1395 		if (!prop) {
1396 			prop = node->deadprops;
1397 			node->deadprops = NULL;
1398 		}
1399 	}
1400 	kfree(node->full_name);
1401 	kfree(node->data);
1402 	kfree(node);
1403 }
1404 
1405 /**
1406  *	of_node_put - Decrement refcount of a node
1407  *	@node:	Node to dec refcount, NULL is supported to
1408  *		simplify writing of callers
1409  *
1410  */
1411 void of_node_put(struct device_node *node)
1412 {
1413 	if (node)
1414 		kref_put(&node->kref, of_node_release);
1415 }
1416 EXPORT_SYMBOL(of_node_put);
1417 
1418 /*
1419  * Plug a device node into the tree and global list.
1420  */
1421 void of_attach_node(struct device_node *np)
1422 {
1423 	write_lock(&devtree_lock);
1424 	np->sibling = np->parent->child;
1425 	np->allnext = allnodes;
1426 	np->parent->child = np;
1427 	allnodes = np;
1428 	write_unlock(&devtree_lock);
1429 }
1430 
1431 /*
1432  * "Unplug" a node from the device tree.  The caller must hold
1433  * a reference to the node.  The memory associated with the node
1434  * is not freed until its refcount goes to zero.
1435  */
1436 void of_detach_node(const struct device_node *np)
1437 {
1438 	struct device_node *parent;
1439 
1440 	write_lock(&devtree_lock);
1441 
1442 	parent = np->parent;
1443 	if (!parent)
1444 		goto out_unlock;
1445 
1446 	if (allnodes == np)
1447 		allnodes = np->allnext;
1448 	else {
1449 		struct device_node *prev;
1450 		for (prev = allnodes;
1451 		     prev->allnext != np;
1452 		     prev = prev->allnext)
1453 			;
1454 		prev->allnext = np->allnext;
1455 	}
1456 
1457 	if (parent->child == np)
1458 		parent->child = np->sibling;
1459 	else {
1460 		struct device_node *prevsib;
1461 		for (prevsib = np->parent->child;
1462 		     prevsib->sibling != np;
1463 		     prevsib = prevsib->sibling)
1464 			;
1465 		prevsib->sibling = np->sibling;
1466 	}
1467 
1468 	of_node_set_flag(np, OF_DETACHED);
1469 
1470 out_unlock:
1471 	write_unlock(&devtree_lock);
1472 }
1473 
1474 #ifdef CONFIG_PPC_PSERIES
1475 /*
1476  * Fix up the uninitialized fields in a new device node:
1477  * name, type and pci-specific fields
1478  */
1479 
1480 static int of_finish_dynamic_node(struct device_node *node)
1481 {
1482 	struct device_node *parent = of_get_parent(node);
1483 	int err = 0;
1484 	const phandle *ibm_phandle;
1485 
1486 	node->name = of_get_property(node, "name", NULL);
1487 	node->type = of_get_property(node, "device_type", NULL);
1488 
1489 	if (!node->name)
1490 		node->name = "<NULL>";
1491 	if (!node->type)
1492 		node->type = "<NULL>";
1493 
1494 	if (!parent) {
1495 		err = -ENODEV;
1496 		goto out;
1497 	}
1498 
1499 	/* We don't support that function on PowerMac, at least
1500 	 * not yet
1501 	 */
1502 	if (machine_is(powermac))
1503 		return -ENODEV;
1504 
1505 	/* fix up new node's linux_phandle field */
1506 	if ((ibm_phandle = of_get_property(node, "ibm,phandle", NULL)))
1507 		node->linux_phandle = *ibm_phandle;
1508 
1509 out:
1510 	of_node_put(parent);
1511 	return err;
1512 }
1513 
1514 static int prom_reconfig_notifier(struct notifier_block *nb,
1515 				  unsigned long action, void *node)
1516 {
1517 	int err;
1518 
1519 	switch (action) {
1520 	case PSERIES_RECONFIG_ADD:
1521 		err = of_finish_dynamic_node(node);
1522 		if (err < 0) {
1523 			printk(KERN_ERR "finish_node returned %d\n", err);
1524 			err = NOTIFY_BAD;
1525 		}
1526 		break;
1527 	default:
1528 		err = NOTIFY_DONE;
1529 		break;
1530 	}
1531 	return err;
1532 }
1533 
1534 static struct notifier_block prom_reconfig_nb = {
1535 	.notifier_call = prom_reconfig_notifier,
1536 	.priority = 10, /* This one needs to run first */
1537 };
1538 
1539 static int __init prom_reconfig_setup(void)
1540 {
1541 	return pSeries_reconfig_notifier_register(&prom_reconfig_nb);
1542 }
1543 __initcall(prom_reconfig_setup);
1544 #endif
1545 
1546 struct property *of_find_property(const struct device_node *np,
1547 				  const char *name,
1548 				  int *lenp)
1549 {
1550 	struct property *pp;
1551 
1552 	read_lock(&devtree_lock);
1553 	for (pp = np->properties; pp != 0; pp = pp->next)
1554 		if (strcmp(pp->name, name) == 0) {
1555 			if (lenp != 0)
1556 				*lenp = pp->length;
1557 			break;
1558 		}
1559 	read_unlock(&devtree_lock);
1560 
1561 	return pp;
1562 }
1563 EXPORT_SYMBOL(of_find_property);
1564 
1565 /*
1566  * Find a property with a given name for a given node
1567  * and return the value.
1568  */
1569 const void *of_get_property(const struct device_node *np, const char *name,
1570 			 int *lenp)
1571 {
1572 	struct property *pp = of_find_property(np,name,lenp);
1573 	return pp ? pp->value : NULL;
1574 }
1575 EXPORT_SYMBOL(of_get_property);
1576 
1577 /*
1578  * Add a property to a node
1579  */
1580 int prom_add_property(struct device_node* np, struct property* prop)
1581 {
1582 	struct property **next;
1583 
1584 	prop->next = NULL;
1585 	write_lock(&devtree_lock);
1586 	next = &np->properties;
1587 	while (*next) {
1588 		if (strcmp(prop->name, (*next)->name) == 0) {
1589 			/* duplicate ! don't insert it */
1590 			write_unlock(&devtree_lock);
1591 			return -1;
1592 		}
1593 		next = &(*next)->next;
1594 	}
1595 	*next = prop;
1596 	write_unlock(&devtree_lock);
1597 
1598 #ifdef CONFIG_PROC_DEVICETREE
1599 	/* try to add to proc as well if it was initialized */
1600 	if (np->pde)
1601 		proc_device_tree_add_prop(np->pde, prop);
1602 #endif /* CONFIG_PROC_DEVICETREE */
1603 
1604 	return 0;
1605 }
1606 
1607 /*
1608  * Remove a property from a node.  Note that we don't actually
1609  * remove it, since we have given out who-knows-how-many pointers
1610  * to the data using get-property.  Instead we just move the property
1611  * to the "dead properties" list, so it won't be found any more.
1612  */
1613 int prom_remove_property(struct device_node *np, struct property *prop)
1614 {
1615 	struct property **next;
1616 	int found = 0;
1617 
1618 	write_lock(&devtree_lock);
1619 	next = &np->properties;
1620 	while (*next) {
1621 		if (*next == prop) {
1622 			/* found the node */
1623 			*next = prop->next;
1624 			prop->next = np->deadprops;
1625 			np->deadprops = prop;
1626 			found = 1;
1627 			break;
1628 		}
1629 		next = &(*next)->next;
1630 	}
1631 	write_unlock(&devtree_lock);
1632 
1633 	if (!found)
1634 		return -ENODEV;
1635 
1636 #ifdef CONFIG_PROC_DEVICETREE
1637 	/* try to remove the proc node as well */
1638 	if (np->pde)
1639 		proc_device_tree_remove_prop(np->pde, prop);
1640 #endif /* CONFIG_PROC_DEVICETREE */
1641 
1642 	return 0;
1643 }
1644 
1645 /*
1646  * Update a property in a node.  Note that we don't actually
1647  * remove it, since we have given out who-knows-how-many pointers
1648  * to the data using get-property.  Instead we just move the property
1649  * to the "dead properties" list, and add the new property to the
1650  * property list
1651  */
1652 int prom_update_property(struct device_node *np,
1653 			 struct property *newprop,
1654 			 struct property *oldprop)
1655 {
1656 	struct property **next;
1657 	int found = 0;
1658 
1659 	write_lock(&devtree_lock);
1660 	next = &np->properties;
1661 	while (*next) {
1662 		if (*next == oldprop) {
1663 			/* found the node */
1664 			newprop->next = oldprop->next;
1665 			*next = newprop;
1666 			oldprop->next = np->deadprops;
1667 			np->deadprops = oldprop;
1668 			found = 1;
1669 			break;
1670 		}
1671 		next = &(*next)->next;
1672 	}
1673 	write_unlock(&devtree_lock);
1674 
1675 	if (!found)
1676 		return -ENODEV;
1677 
1678 #ifdef CONFIG_PROC_DEVICETREE
1679 	/* try to add to proc as well if it was initialized */
1680 	if (np->pde)
1681 		proc_device_tree_update_prop(np->pde, newprop, oldprop);
1682 #endif /* CONFIG_PROC_DEVICETREE */
1683 
1684 	return 0;
1685 }
1686 
1687 
1688 /* Find the device node for a given logical cpu number, also returns the cpu
1689  * local thread number (index in ibm,interrupt-server#s) if relevant and
1690  * asked for (non NULL)
1691  */
1692 struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
1693 {
1694 	int hardid;
1695 	struct device_node *np;
1696 
1697 	hardid = get_hard_smp_processor_id(cpu);
1698 
1699 	for_each_node_by_type(np, "cpu") {
1700 		const u32 *intserv;
1701 		unsigned int plen, t;
1702 
1703 		/* Check for ibm,ppc-interrupt-server#s. If it doesn't exist
1704 		 * fallback to "reg" property and assume no threads
1705 		 */
1706 		intserv = of_get_property(np, "ibm,ppc-interrupt-server#s",
1707 				&plen);
1708 		if (intserv == NULL) {
1709 			const u32 *reg = of_get_property(np, "reg", NULL);
1710 			if (reg == NULL)
1711 				continue;
1712 			if (*reg == hardid) {
1713 				if (thread)
1714 					*thread = 0;
1715 				return np;
1716 			}
1717 		} else {
1718 			plen /= sizeof(u32);
1719 			for (t = 0; t < plen; t++) {
1720 				if (hardid == intserv[t]) {
1721 					if (thread)
1722 						*thread = t;
1723 					return np;
1724 				}
1725 			}
1726 		}
1727 	}
1728 	return NULL;
1729 }
1730 EXPORT_SYMBOL(of_get_cpu_node);
1731 
1732 #if defined(CONFIG_DEBUG_FS) && defined(DEBUG)
1733 static struct debugfs_blob_wrapper flat_dt_blob;
1734 
1735 static int __init export_flat_device_tree(void)
1736 {
1737 	struct dentry *d;
1738 
1739 	flat_dt_blob.data = initial_boot_params;
1740 	flat_dt_blob.size = initial_boot_params->totalsize;
1741 
1742 	d = debugfs_create_blob("flat-device-tree", S_IFREG | S_IRUSR,
1743 				powerpc_debugfs_root, &flat_dt_blob);
1744 	if (!d)
1745 		return 1;
1746 
1747 	return 0;
1748 }
1749 __initcall(export_flat_device_tree);
1750 #endif
1751